This invention relates to the intracorporeal delivery of elongated therapeutic and diagnostic probe devices and particularly to such devices for the treatment of benign prostatic hyperplasia (BPH).
BPH is the enlargement of the prostate gland which frequently occurs in men as they grow older. The enlarged gland can constrict the urethral canal, interfering with the flow of urine through the canal. Treatment modalities for the BPH condition has varied over the years. For many years constricted urethral passageways were dilated by passing bogies with increasing larger distal tips through the constricted passageway. More recently, a similar method has been employed whereby a catheter having a dilatation balloon on its distal end is advanced through the patient's urethra until the dilatation balloon is disposed within the stenotic region and then the balloon is inflated to dilate the urethral passageway. The expansion of the urethral canal through the stenotic region can be effective in expanding the passageway, but the benefits are frequently short-lived, in that the constriction returns after a year or two after the initial dilatation.
The most frequently used modality is the transurethral resection of the prostate (TURP) which involves insertion of a resectoscope through the urethra and removing the constricting tissue by means of a hot wire. However, such surgery can result in incontinence, impotence and a variety of other problems. It usually requires general anaesthesia and a significant hospital stay.
Another treatment modality of more recent origin involves debulking the prostate gland by laser energy which is delivered into the gland by means of an optical fiber. For example, PCT application WO 92/10142 (Makower) describes the utilization of a catheter which is advanced into the patient's urethral canal until its distal end is situated within the prostatic urethra and an elongated needle is curved out of the distal end of the catheter into an adjacent lobe of the patient's prostate gland. An optical fiber is advanced through the inner lumen of the needle into the prostate gland and laser energy is emitted from the distal end of the optical fiber to ablate prostatic tissue. A preferred embodiment has facilities to advance a pair of elongated needles, one needle into each lobe of the prostate gland.
A laser based BPH treatment device of different design is commercially available from the Indigo Medical, Inc.
While laser based devices for BPH treatment procedures have shown promise, they have not been found to be suitable for out-patient use because these procedures use rigid cystoscopes usually requiring general anesthesia and frequently involve extended hospital stays. Due to the extended hospital stays, the treatment costs for laser based BPH treatments are not much less than the costs for TURP.
The laser devices have not been used with flexible cystoscopes because the working channels of the latter is not large enough. Moreover the shaft of the flexible cystoscope does not provide firm enough support for the optical fiber of the laser device to facilitate passage through the urethral wall and into the patient's prostate gland.
What has been needed is a laser based system which can be used with a flexible cystoscope so as to not require general anesthesia and which would facilitate BPH procedures in the physician's office. The present invention satisfies these and other needs.